the search for more answers after the school shooting in newtown connecticut. scientists look into what could have motivated the gunman. and, for the second time in a month a person is pushed to their death in front of a new york subway. he is scheduled to make a formal announcement at some point tomorrow. the earlier this month he was arrested at the airport when security inspectors found a gun on his carry-on bag. he claimed he used the gun at his other job with a security company and forgot he packed it. the american embassy in the central african republic is temporarily closed, and american citizens are being told to evacuate the country. rebel forces in the central african republic have seized territory, and are now advancing upon the capital city of bangui. and the state department fears another violent struggle for power. the country's president is pleading with foreign leaders to help him fend off the rebels. russian president vladimir putin has signed a controversial bill barring americans from adopting russian children. the bill could become law as ea